Automatic pistol



D. H. STEVENSQN.

AUTOMATIC msToL. MfPLlCATlON FILED AUG.5, 1920.

Patenbedsept. 5, 1922.

l3 SHEETS-SHEET l.

D. H. STEVENSON'.

AUTOMATlC PISTOL.

APPLICATION msn AuG.-5, |920.

1,428,304. Patentedsep. 5, 1921).'

3 SHEETS-SHEET 2.

5/ ame/nm D. H. STEVENSON. AUIQMATIC PlsToL.

APPLICATION FILED AUG.5, 1920. i

PatentedSept. 5, 1922.

3 SHEETS-SHEET 3 of Montana,

use the same, reference DONALD H. STEVNSQN, 0F GARDNER, MONTANA.

AUTOMATIC PISTOL.

ppneation med august 5, 1920. serial No.'4o1,41s.

To all 'whom t may concern:

Be it known that I, DONALD H. STEVEN- soN a citizen of the UnitedStates, residing at Gardner, in the county of Parkand State haveinvented certain new and useful Improvements in Automatic Pistols; and Ido hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled intheart to which it appertains to make and being had to the acand to theletters and companying drawings, h

whic

figures of referencemarked thereon, form a part of this specification.

This invention relates to automatic firearms and especially toautomaticpistols and has foi` an object to provide a weapon of thisclass embodying a new and improved type of breech block. 1

A further object of the invention is to' provide in a weapon of thisclass a new and improved type of firing pin co-acting with p the new andimproved breech block.

improved type o A further object of the invention is to provide in a weaon of this class a new and sear co-acting with the lirpin and breechblock.

ing

further object of the invention is to provide new and improved actuatingmeans for the several organized parts', consisting of the breech block,firing pin and sear. A further object of the invention is to provideimproved safety means for maintainin the weapon against the possibilityof accidental discharge.

With these and other objects in View, the invention comprises certainnovel parts,"elel ments, units, combinations, 4mechanical movev ments,functions and inter-actions as disclosed in the drawings together withmechanical equivalents thereof as will be hereinafter more fullydescribed and claimed.

The invention, in its preferred form, is clearly disclosed in theaccompanying drawings, forming a part of my specification, and' in whichlike reference characters videntify corresponding parts throughout theseveral views. Briefiy described:

lFigure 1 is a view, partly in central vertical longitudinal section andpartly in elevation, of my automatic fire-arm, the parts of the firingmechanism being in so-called cocked position;v l

Figure 2 is a similar view, showing the position the parts assume at theextreme breec tension, 3 the handle grip and 9 prise co-operatinextension 2 and t e receiver 4. In the exlimit of their movement underthe influence of recoil;

Figure l3 is a similar view, showing the posltion of the parts atthemoment of explosion;

Figure 4 is a detached'detail view in side elevatlon of the firing-pinstructure; Figure 4 is a perspective view of the firme pin disassociatedfrom its accessories.

Figure 5 1s a detached! detail view in side elevation of the breechblock;

Fi ure 5a is a perspective view of the block removed.

Figure 6 is a fragmentary detached detail view in perspectiveof aportion of the safety mechanism;

Figure 7 is a fragmentary detail view in section of the sear, breechblock, and of certain parts carried thereby; Y

Figure 8 is a detached detail view in perspective of a sear engagingmember carried by the trigger; y

Figure 9 is a detached fragmentary detail view in erspective of `therear portion of thebarre extension, and showing more particularly tworibs carried thereby and upon which the breech 'block rides duringrecoil;

Figure 10 is a detached detail view in perspective of onel of the safetymembers;

Figure 11 'is a detached detail view in side elevation of part of themechanism for withdrawing the firing-pin, and compresses the firing-pinspring during recoil, and

Figure 12 is a detached detail view in side elevation, 1partly insection, of the parts shown in igure 11,-together with certainassociated parts, and showing also a portion of the breech block andfiring-pin structure.

Referring now in detail to the drawings:

1 designates the barrel, 2 the barrel exthe triggerguard of my automaticpistol. The barrel '1 is detachably secured to the barrel extension 2 inany suitable manner so that the two parts constitute a ri id unitarystructure, adapted to slide a slig t distance (preferably three-eighthsof an inch) upon the receiver 4 shown atw Fig. 1. Suitable means areprovided for limlting the rearward movement of the barrel 1 and itsextension 2 and, in this instance, such means perfera'bly comelementscarried by the empliied form of suchl means, the forward portion 5 ofthe receiver 14 is recessed, as

shown at 6,-fdrming a rear shoulder 7, en-

The .grip 3 -is.provided, at the bottom of its front wall, withaprojection 10, provided with a curved upper wall 11, confo rming tothecurvature of the hand of the operator;

- f This projection functions to keep the operators hand from slippingdown, andsupports the bottom of the hand.

12 designates the breech block, slidabl mounted at the forward end ofthe rear holY low shell-like portion l2 of the barrel extension 2, andadapted to open and vclose the breech 16. The breech parts.

Normally the breech block is firmly held against the rear Vend of thebarrel 1 by being wedged against the inner ends o longitudinally'extending ribs 23, carried on the in- 4 fao ner surfaceof the' sidewalls of the barrel ex- Y .tension shell 2', the upper longitudinal edgeof eachrib being inclined .with reference to the axis of the barrel 1 inan upward direction from the inner to the outer end of the rib,saidinclined edge being identified by the reference. numeral 24.

The ri'ng-pin, of peculiar construction, comprises the firing-pinproper, 17, a tubular member`18, having a'closed end, from which saidfiring-pin properl projects in line with the axisof said member, andtworearward projecting arms 19, 19, having each a longitudinallyextending slot 20 and a lateralrear bridge' 23, connecting said-arms,the member 18 carrying at its top,a projection 21, having, as shown, afront wall at right angles to the laxis of said member and v a rear wallinclined to said rst-mentioned wall. This pro'ection 21, in the forwardposition of the ring-pin within the breech block 12, enters an internalrecess 22 in the latter. The firing-pin tubular member 18 is slidable,as usual, within the longitudinally extended recess 13 in the breechblock 12. The firing-pinproper 17, in the extreme forward positionthereof,pro'jects through an aperture 14 in the forward end of thebreech block.

block and extend through slots 20 vof the The searof my pistol comprisesan arm 25r depending, in a forward and downward curved direction, from apivot at 26, the ends of said pivot being carried by the breech arms 19,19 of the firing-pin barrel`18 and through the sear which issubstantially a bell crank lever as will be hereinafter more fullydescribed. The arm 25 has a toe 26' engaged by the extremity of theshorter arm 2 1', having a beveled end 21, of 4a bell crank lever,fulcrumed on a pin 28, carried toward the upper end'of the trigger 29,pivoted at 30' to the receiver 4, the extremity of the Vlonger arm'27 ofsaid lever bein or inclined, ,as shown at 31, an

block is peculiarly formed and will be'particularly described inconnection with co-operating or associated linside the tubular, or

movable against a correspondingly inclined shoulder 32, interiorly ofthe barrel extension 2, toward the frontend thereof. Said arm 25 alsocarries 'a vfinger 33 in advance of the' toe 26 and adapted to beengaged by a safety projection or toe, 34, angularly and laterallycarried by va pin 34 angularly supported at the Aupper end of a bar 35,more particularly hereinafter described.

vThe Sear also carries at itspivotal end a downward projecting toe 36,against which rests the head 37 of a preferably tapering pin 38,projecting into the tubular portion 18 of vthe firing-pin and encircledby the firingpin driving spring 39, disposed, as usual,

end of said spring bearing against the closed end of said member 18 andthe other end against the head 37.

The pivot at 26 also passes through the rear portion of aforward-projecting arm 40, provided with a hook-extremity 41, havi lng alower inclined, or beveled, edge 42, said 43 in the rear of the breechblock l2 are the I ends of a crosshead 44, carried at the projectingupper end of -and integral-or rigid vWith a bell crank lever'45,*pivoted at one end thereof,y as shown at 46, to one end of a link47, the latter being pivoted at its.

barrel, portionA 18, one

opposite end, as shown at 48, to ears 49,

internally carried by the vhandle gip 3, toward the upper rear endthereo The longer arm of said bell crank lever 45 normally projectsin anupward and forward direction from the pivot 46,l as shown in Figure 1. lSaid longer arm of the lever also rigidly carries, at its upperend, amember 50, formed asa beak, adapted inthe recoil movement of -the parts,to contact against the bridge 23 ofthe lirin -pin for a purpose whichwill appear -in t edescription of the operation' of the mechanism` Theshorter arm of the bellcrank lever 45V I is. provided with ahook-extremity'l, en-` gaging one end of afstirrup 52, the other end ofsaid stirrup 'engaging theY hook-y extremity 53 of a rod 54, carrying atits vother end, a head 55. Encircling the said,V at one end against saidrod 54 and bearin headand, at the'ot er end against theV 'upper end of ahousing. 56, carriedat lthe rear of .A leaf spring position shown inFigure 1 and the the hand grip 3, `is a coil spring- 57. The head 55moves and is guided in a suitable recess, or` pocket, 58, formed by thehousing 56 Vbears against the pin 62, .carried by Vsaid trigger, and theopposite end against the longer arm of the bell crank lever 27, saidspring tendingv to rockt saidl longer arm ward. The safety arm 35,carrying the safety projection 34, previously referred to, v\is pivoted,toward its lower end, on a pivot' pin 63, carried by the hollowprojection 10. 64 is coiled around said pivot pin 63 and one end thereofbears against the inner surface of the front wall of the hand grip 3,and the other end againsty the lower portion of the arm, or bar, 35, andtends to throw said arm toward the rear of the handle grip. The bar 35is provided with an expanded portion 65, intermediate its ends, whichprojects rearward through an opening 66 in the rear wall of the grip 3,and is provided at its end with the angled grip portion 67, having aprojection 68.

The bar 35 also carries, above the expanded part 65, 'a projection 69 onits front edge, which projection is in line with a recess 70 of the grip3, adjacent the tri ger guard 9.

ommon means for locking said bar 35 and the trigger 29 against movement,is provided and in this instance comprises a safety member round incross section, rotatably carried by the hand grip 3, adjacent thetrigger guard 9, and 4provided with diametrically oppositecircumferential cutaway portions 72, 72. When the safety member 71 isturned to a position so as to bring the recesses 72, 72 in line with thepathof travel of the trigger 29 and the projection 69, said trigger maybe moved rearward into the corresponding recess 72, and the projection69 maybe moved into the other recess 72; and conversely, when therotatable member 71 is moved so as to bring said recesses out ofregister with the trigger and projection 69, it will be impossible tomove said trigger and projection.

The operation of the mechanism of my pistol is as follows:

Assuming the parts to be in the cocked safety 34 rocked out ofengagement with the finger 33 of the sear by the act of the shooterfirmly grasping the hand grip 3 and pressing upon the projection 68andthe portion at a point thereonV 67 of the safety bar 35,' pressureupon the trigger 29 will 'move the same upward upon its pvot 30, therebysimultaneously raising.

the bell crank lever 27 and consequently rocking upward the the catcharm 40 of the searupward, disengaging `the hook 41 thereof from theprojection 21 of the firing-pin barrel 22.l The firing-pin drivingspring 39 now functions to drive the firing-pin forward to penetrate'the cartridge primer, thus exploding the cartridge, or shell; Recoilnow ensues con- Sear` arm 25, which. tiltsseqllent uponV theexplosion,driving the barrel 1 and the barrel extension'2 and breech block 12,with the parts contained therein,

rearward three-eighths of an inch. The

breech block 12, at the beginning of this recoil movement, 4is firmlylocked against ythe rear of the barrel by being wedged in front of thelugs 23 of the barrel extension shell 2. As said, the barrel, the barrelextension and breech block move back together three-eighths of an inchuntil the projection 8, carried by the barrel extension 2, contacts withthe shoulder 7 of the portion 5 of the receiver 4, whereupon furthermovement rearward of said barrel and barrel extension is arrested.

During thisdescribed movement of threeeighths of an inch travel, thebell crank lever 45 is rocked on the pivot 46 so that the longer arm ofsaid lever moves from the inclined position thereof, shown in Figure 1,to a substantially perpendicular position,- that is, a positionsubstantially at right angles to the axis of the barrel 1,-the ends ofthe prin 44 consequently riding out of the bottom of the recesses 43 inthe breech block 12 and contacting with the walls 43 of said recesses.The continued upward pressure upon said walls 43 exerts an upward stressu on the breech-block, which is consequently ti ted upward so as toremove the rear lower end of the breech block out of contact with thefront ends of the ribs 23, bringing the bottom of the breech block inline with the top edges of said ribs. The breech block is now free tocontinue its recoil movement, and, since the barrel and barrel extensionare locked, as stated, said breech block now moves rearward under theforce of recoil independent of said barrel and barrel extension, saidbreech block sliding upon the inclined top surfaces 24 of the ribs 23.The bell crank lever 45, by reason of the extended engagement 0f theends of the crosshead 44 in the rear recesses 43 of the breech block,is, during the said independent recoil movement of the breechblock,thrown from the perpendicular position previously referred to to theposition shown in Figure 2, this figure showing the extreme rearwardrecoil position of the parts.

During this independent recoil movement of the breech block, the bellcrank lever 45 pulling upward upon the stirrup 52 and drawing the rod 54upward, thus placing the stirrup 52 under tension of the compressedspring 57.

During said independent recoil movement of the breech block l2, themember 50, carried by the lever 45, is thrown into contact with thebridge 23 of the arms 19. As the member 50 is thrown rearward bythe-lever 45, the arms 19 are pulled so as to move 'the firing-pintubular member 18 rearward, in-v dependently of the rearward movement ofthe breech block 12, thereby bringing the inclined edge of theprojection 21 into contact with the inclined edge 42 ofthe catch 40,until the said projection passes to the rear of the lower end of saidinclined edge 42, whereupon said catch 40 drops,.so as to engage thehooked terminal of said catch with said projection, as shown in Figure2,

thereby compressing the tiring-pin driving spring 39. v

The p-arts being now in the position shown in Figure 2, the tensionexpands, driving the rod 54downward, thus pulling the shorter arm of thebell crank lever 45 downward, thereby moving the link 47 from theposition thereof shown in Figure 2 to the position shown in Figure 1,.and consequently moving the breech block 12 forward'. The breech blockfinally drops downward behind the lu 23.`

The .exploded shell is removed or extracted, by any suitable mechanism,not constituting a part of this invention, such mechamsm bein well knowninthe art.

What claim to be new is:

- 1. In a lire-arm the combination 'with a, slidable barrel and barrelextension, of a breech block within said barrel extension, ribs disposedon the inner faces of the side walls of the barrel extension andlextending longitudinally thereof, the upperlongitudinal edges of saidribsbeing. inclined to the axis ofthe barrel, lsaid inclined edgesextending upward 'and rearward. from the front ends of saidwribs, therear end-.of said breech block nrmally bearing against theYforward-'ends-of said ribs, andmeans operable'. l'at the end of therecoil lmovement of said barrel and barrel extension to tilt therearendof said breech block upward, out of locking-engagement with.-Isaid ribs. Y

^ 2. In a' fire-arm the combination Awith a slidable barrel and barrelextension, of a breech block within said barrel extension,

ribs disposed on the inner faces of the side walls-of 'the barrel-extension and `extending coil spring 57 now longitudinally thereof, theupper longitudinal edges of said ribs being inclined to the cluding alever loosely engaging said breech block.

3. In a lire-arm the combination with a' slidable barrel and barrelextension, of -a breech block within said barrel extension, ribsdisposed on the inner faces ofthe side walls of the barrel extension andextendin longitudinallythereof, the upper longitudlnal edges of saidribsy being inclined to the axis of the barrel, said inclined ,edgesextending upward and rearward from the front ends of said'ribs, the rearend of said breech block normally bearing against the forward ends ofsaid'ribs,'and means operable at the end of the recoil movement of saidbarrel and barrel extension to tilt the rear end of said breech blockupward, out of locking engagement, with said ribs, sa1d means includinga movably fulcrumed lever,

-loosely engaging said breech block.

Aforward ends of said ribs, means operable at the endof the recoilmovement of said 'barrel and barrel extension to tilt the rear end ofsaid breech block upward, out of locklng engagement with said ribs, saidmeans 1ncluding a lever loosely engaging said breech block,'and a linkpivoted to `said lever. A

5; In a lire-arm the combination with a slidable barrel and barrelextension, of a breech block within said barrel extension, l

ribs disposed'on the inner faces of the side walls of the barrelextension and extending longitudinally thereof, the upper longitudinaledges of said ribs being inclined to the axis 'of thev barrel, -saidinclined edges extending. upward and rearwardv lfrom thel front ends ofsaid ribs, the rear end of said l?? breech block normally vbearingagainst the forward endn of said ribs, able attheend of the recoilmovement of said barrel and barrel extension to tilt the rear end ofsaid breech block upward, out of locking engagement with said ribs, saidcoi-121.11.

said `breech block, and Spring Cori/@rolled means connected with saidvlever for barrel and means including a lever having projections looselengaging said breech block.

6. yn a fire-arm the combination with a slidable barrel and barrelextension, of a breech block'within said barrel extension, ribs disposedon the inner faces of the side walls of the barrel extension andextending longitudinally thereof, the upper longitudinal edges of saidribs being inclined to the axis of the barrel, said inclined edgesextending upward and rearward from the front ends of said ribs, the rearend ofsaid breech block normally bearing against the forward end of saidribs, and means operable at the end of the recoil movement of saidIbarrel and barrel extension to tilt the rear end of said breech blockupward, out of locking engagement with said ribs, said means including alever carrying a pin, the ends of which loosely engage said breechblock.

7 In a re-arm, the combination with a slid-able barrel and barrelextension, or a breech block within said barrel extension, a firin -pinstructure slidably projecting within said breech block, ribs disposed onthe' inner faces of the side walls of the barrel extension and extendinlongitudinally thereof, the upper longitu inal edges of said ribs beinginclined to the axis of the barrel, said inclined edges extending upwardand rearward from the front ends of said ribs, `the rear end of saidbreech block normally -bearing against the forward ends of said rlbs,means including a lever o erable atl the end of the recoil movement osaid bar- 'rel and barrel extension to tilt the rear end of said breechblock upward, out of locking engagement with said ribs, and a membercarriedby said lever and engageable with said tiring-pin structure inthe recoil movement of the breech block to force the ring pin structurerearward, independentv of the recoiling breech block. v

8. In a fire-arm `the combination with a slidable barrel and barrelextension, of a breech block within said barrel extension, ribs disposedon the inner faces of the side walls of the barrel extension andextending longitudinally thereof, the upper longitudinal edges of saidribs being inclined to the axis of the barrel, said inclined edgesextending upward and rearward from the front ends of said ribs,- therear end of said breech block normally bearing against the forward endsof said ribs, and means operable at the end ofthe recoil movement ofengagement with said ribs, said cans including a lever loosely engagingtothrow the' latter forward.

- 9. In a fire-arm the combination slidable barrel and barrelpextension,of ai breec' barrel extension to tilt the` IvTiear end of said breechblock upward, out of block within said barrel extension, ribs disposedon the inner faces of the side walls of the barrel extension andextending longitudinally thereof, the upper longitudinal edges of saidribs being inclined to the axis of the barrel, said inclined edgesextending upward and rearward from the front ends of said ribs, the rearend of said breech block normallyA bearing against the forward ends ofsaid ribs, and means operable at the end-of the recoil movement of ,saidbarrel and barrel extension to tilt the rear end of said breech blockupward, out of locking engagement with said ribs, said. means includinga bell crank lever, the longer arm of which loosely engages said breechblock, and spring controlled means connected with the shorter arm ofsaid lever and tending to throw said lever forward.

10. In a lire-arm the combination with a slidable barrel and, barrelextension, of a breech block within said barrel extension,

ribs disposed on the inner faces of the side walls of the barrelextension and extending longitudinally thereof, the upper longitudinaledges of said ribs being inclined to the axis of the barrel, saidinclined edges extending .upward' and rearward from the front ends ofsaidribs, the rear end of said breech block normally bearing against theforward ends of said ribs, and means operable at the end of the recoilmovement of said barrel and barrel extension to tilt the rear end ofsaid breech block upward, outof locking engagement with said ribs, saidmeans including a bell crank lever, the longer arm of which looselengages said breech block, a member loose y engaging the shorter arm ofsaid lever, and a spring controlled rod loosely engaging said member andtending to throw said lever forward.

11. In a fire-arm the combination with a slidable barrel and barrelextension, of a breech block within said barrel extension, ribs disposedon the inner faces of the side' walls of the barrel extension andextending longitudinally thereof, the upper longitudinal ed es of saidribs .being inclined to the axis o the barrel, said inclined edgesextending upward and rearward from the front ends of said ribs,vthe rearend of said breech block normally bearing against the forward ends ofsaid ribs, and means operableat the end' of the recoil movement of saidbarrel and barrel extension -to tilt the rear end of said breech blockupward, out o-f locking engagement with said ribs, said means includinga lever loosely engaging said breech block, and a pivoted link to whichsaid lever is pivotally secured, .and meansfor limiting the pivotalmovement of said-l in one dlrectiom i Ii, mony whereof I hereunto aiixmy signa-- DONALD H. STEVENSON.

